Feature/gaia mission merge (#766)

* Add Adam Aslegård's module that renders Gaia mission stars
 * Add module for Gaia mission
 * Add CCfits and cfitsio submodules and the implemented fitsfilereader module from the OpenSpace-sun-earth-event branch
 * Add a TaskRunner to read from a fits file

modules/sync/tasks/syncassettask.cpp

@@ -36,6 +36,12 @@
 #include <openspace/util/synchronizationwatcher.h>
 #include <ghoul/filesystem/filesystem.h>
 #include <ghoul/logging/logmanager.h>
+#include <ghoul/lua/luastate.h>
+
+#include <string>
+#include <fstream>
+#include <chrono>
+
 #include <thread>
 
 namespace {